Compensate for chamber and process effects to improve critical dimension variations in trim processes

Abstract

A controller includes a memory storing data associating cumulative values ​​with corresponding adjustment factors. The cumulative values ​​correspond to the accumulation of material on a surface within a processing chamber, and the corresponding adjustment factors correspond to adjustments to control parameters of radio frequency (RF) power provided to the processing chamber. A cumulative calculation module is configured to calculate a first cumulative value, the first cumulative value indicating the amount of accumulation of the material. An RF power control module is configured to: receive the first cumulative value; receive at least one of a setpoint power and a duration of the etching step; retrieve the stored data from the memory; adjust the control parameter based on the first cumulative value, the setpoint power and the duration of the etching step, and the stored data; and control the RF power provided to the processing chamber according to the adjusted control parameter.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Patent Application No. 16 / 053,022 filed on August 2, 2018. The entire disclosure of the above-referenced application is incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a double patterning process in an atomic layer deposition substrate processing chamber. Background Art

[0004] The background description provided here is for the purpose of generally presenting the context of the present disclosure. The work of the presently designated inventors is neither explicitly nor implicitly admitted to be prior art against the present disclosure to the extent that it is described in this background section and in aspects of the specification that were not determined to be prior art at the time the application was filed.

[0005] Substrate processing systems can be used to process substrates, such as semiconductor wafers. Examples of substrate processing include etching, deposition, photoresist removal, etc. During processing, a substrate is placed on a substrate support, such as an electrostatic chuck, and one or more process gases can be introduced into a processing chamber.

[0006] The one or more process gases may be delivered to the process chamber by a gas delivery system. In some systems, the gas delivery system includes a manifold connected to a showerhead located in the process chamber by one or more conduits. In some examples, the process utilizes atomic layer deposition (ALD) to deposit a thin film on a substrate. Summary of the invention

[0007] A controller includes a memory storing data associating cumulative values ​​with corresponding adjustment factors. The cumulative value corresponds to the accumulation of material on a surface within a processing chamber, the processing chamber being configured to perform etching and deposition on a substrate, and the corresponding adjustment factor corresponds to an adjustment of a control parameter for radio frequency (RF) power provided to the processing chamber when performing an etching step of a patterning process. A cumulative calculation module is configured to calculate a first cumulative value, the first cumulative value indicating the amount of accumulation of the material. An RF power control module is configured to: receive the first cumulative value; receive at least one of a set value power and a duration of the etching step, the set value power to be provided during the etching step; retrieve the stored data from the memory; adjust the control parameter based on the first cumulative value, the set value power and the duration of the etching step, and the stored data; and control the RF power provided to the processing chamber during the etching step according to the control parameter as adjusted.

[0008] In other features, the control parameter is the amplitude of the RF power, and wherein the RF power control module is configured to use the stored data to determine a first adjustment coefficient corresponding to the first cumulative value and to adjust the amplitude of the RF power according to the first adjustment coefficient. The stored data is a polynomial that relates the cumulative value to the corresponding adjustment coefficient. The first adjustment coefficient is a ratio of the amplitude of the RF power required to compensate for the accumulation to the set value power. The RF power control module is configured to multiply the set value power by the first adjustment coefficient to adjust the control parameter.

[0009] In other features, the cumulative calculation module is configured to calculate the first cumulative value based on at least one of the number of etching steps performed in the processing chamber, the number of cycles of etching steps and deposition steps performed in the processing chamber, the total duration of etching steps and deposition steps performed in the processing chamber, and the number of substrates processed in the processing chamber.

[0010] In other features, the control parameter is the duration of the etching step, and the RF power control module is configured to use the stored data to determine a first adjustment factor corresponding to the first cumulative value, and to adjust the duration of the etching step according to the first adjustment factor. The first adjustment factor corresponds to an amount for increasing the duration of the etching step to compensate for the accumulation. The RF power control module is configured to multiply the duration of the etching step by the first adjustment factor to adjust the control parameter. The etching step is a trimming step. A system includes the controller, and the controller is further configured to perform a spacer layer deposition step in the processing chamber after the trimming step.

[0011] A method includes: storing data associating cumulative values ​​with corresponding adjustment factors. The cumulative values ​​correspond to accumulation of material on a surface within a processing chamber, the processing chamber being configured to perform etching and deposition on a substrate, and the corresponding adjustment factors correspond to adjustments to control parameters for radio frequency (RF) power provided to the processing chamber when performing an etching step of a patterning process. The method also includes: calculating a first cumulative value, the first cumulative value indicating the amount of accumulation of the material; receiving at least one of a setpoint power and a duration of the etching step, the setpoint power to be provided during the etching step; adjusting the control parameter based on the first cumulative value, the setpoint power and the duration of the etching step, and the stored data; and controlling the RF power provided to the processing chamber during the etching step according to the control parameter as adjusted.

[0012] In other features, the control parameter is the amplitude of the RF power, and the method further includes: determining a first adjustment coefficient corresponding to the first cumulative value using the stored data; and adjusting the amplitude of the RF power according to the first adjustment coefficient. The stored data is a polynomial that relates the cumulative value to the corresponding adjustment coefficient. The first adjustment coefficient is a ratio of the amplitude of the RF power required to compensate for the accumulation to the set value power. The method further includes multiplying the set value power by the first adjustment coefficient to adjust the control parameter.

[0013] In other features, the method further includes calculating the first cumulative value based on at least one of the number of etching steps performed in the processing chamber, the number of cycles of etching steps and deposition steps performed in the processing chamber, the total duration of etching steps and deposition steps performed in the processing chamber, and the number of substrates processed in the processing chamber.

[0014] In other features, the control parameter is the duration of the etching step, and the method further includes: using the stored data to determine a first adjustment factor corresponding to the first accumulation value, and adjusting the duration of the etching step according to the first adjustment factor. The first adjustment factor corresponds to an amount for increasing the duration of the etching step to compensate for the accumulation. The etching step is a trimming step, and the method further includes: performing a spacer layer deposition step in the process chamber after the trimming step.

[0015] Further scope of applicability of the present disclosure will become apparent from the detailed description, claims and drawings.The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present disclosure will be more fully understood from the detailed description and accompanying drawings, in which:

[0017] Figure 1 is a functional block diagram of an example of a substrate processing system according to the present disclosure;

[0018] Figures 2A to 2K An example of a double patterning atomic layer deposition process is shown according to the present disclosure;

[0019] Figures 3A to 3D An exemplary trimming step of a self-aligned double patterning process is shown according to the present disclosure;

[0020] Figure 4 shows an exemplary decrease in etch volume with increasing material accumulation in a processing chamber in accordance with the present disclosure;

[0021] Figure 5 shows exemplary radio frequency (RF) power relative to etch amount according to the present disclosure;

[0022] Figure 6 is a table showing exemplary changes in etch volume and effective power with increasing accumulation in a processing chamber according to the present disclosure;

[0023] Figure 7 shows an example graph of power adjustment factors calculated at various accumulation values ​​in accordance with the present disclosure;

[0024] Figure 8 An exemplary method for compensating for buildup in a process chamber to minimize wafer-to-wafer (WtW) variability in a trim step according to the present disclosure; and

[0025] Fig. 9 An exemplary controller configured to compensate for buildup in a process chamber according to the present disclosure is shown.

[0026] Among the drawings, reference numerals may be repeated to identify similar and / or identical elements. DETAILED DESCRIPTION

[0027] In film deposition processes such as atomic layer deposition (ALD), various properties of the deposited film vary in spatial (i.e., xy coordinates in a horizontal plane) distribution. For example, a substrate processing tool may have a corresponding specification for film thickness non-uniformity (NU), which may be measured as a full range, half range, and / or standard deviation of a set of measurements taken at predetermined locations on the surface of a semiconductor substrate. In some examples, NU may be reduced by, for example, addressing the direct cause of the NU and / or introducing a countervailing NU to compensate for and eliminate existing NU. In some examples, material may be intentionally deposited and / or removed non-uniformly to compensate for known non-uniformities of other (e.g., previous or subsequent) steps in the process.

[0028] A double patterning (DPT) ALD process, such as a self-aligned double patterning (or SADP) process, may include steps including, but not limited to, a photolithography step, a trimming step, and a sacrificial spacer deposition step. Each step may have an associated NU that affects the NU and imbalance of the overall critical dimension (CD). For example, a trimming step may be performed between the photolithography step and the spacer deposition step to reduce the CD. However, trimming NU may result in non-uniform double patterning, which increases the CD imbalance phenomenon and leads to poor yield. The trimming NU may be characterized as radial NU and azimuthal NU.

[0029] The CD NU and imbalance of a particular substrate can be characterized by within-wafer (WiW) variability. Conversely, the CD NU and imbalance between different substrates can be characterized by wafer-to-wafer (WtW) variability. In a DPT process, it may be difficult to minimize the WtW variability in CD NU and imbalance. For example, a trimming step and a subsequent spacer deposition step may be performed in the same processing chamber to increase processing throughput. The deposition step causes material to accumulate on surfaces (e.g., inner walls) within the processing chamber. In addition, etching byproducts (e.g., byproducts of the trimming step) accumulate on the surfaces of the processing chamber. This accumulation of material in the processing chamber changes the overall impedance of the processing chamber, which in turn affects the etching rate. Therefore, the accumulation of material and the resulting changes in the chamber impedance increase the WtW variability of the trimming step.

[0030] Systems and methods according to the principles of the present disclosure are configured to reduce WtW etching variability (e.g., in a trim step) that is caused by material accumulation on the inner surface of the processing chamber. For example, the etching rate is also affected by the radio frequency (RF) power provided to the electrode to generate the plasma within the processing chamber. Therefore, in one example, as the etching rate decreases due to this accumulation, the control parameter of the RF power can be adjusted to compensate for the decrease in etching rate. In one example, the control parameter is the amount (i.e., amplitude) of RF power provided during the trim step. In other words, the RF power can be adjusted to maintain the desired etching rate and reduce the variability caused by changes in the impedance of the processing chamber. In another example, the control parameter is the duration of the etching (e.g., the duration of the trim step), and the duration can be increased to compensate for the decrease in etching rate.

[0031] Reference Figure 1 , shows an example of a substrate processing system 100 including a substrate support (e.g., an ALD pedestal) 104 according to the present invention. The substrate support 104 is disposed within a processing chamber 108. During processing, a substrate 112 is disposed on the substrate support 104.

[0032] The gas delivery system 120 includes gas sources 122-1, 122-2, ..., and 122-N (collectively referred to as gas sources 122), which are connected to valves 124-1, 124-2, ..., and 124-N (collectively referred to as valves 124) and mass flow controllers 126-1, 126-2, ..., and 126-N (collectively referred to as MFCs 126). MFCs 126 control the flow of gases from gas sources 122 to manifold 128, where the gases are mixed. The output of manifold 128 is supplied to manifold 136 via optional pressure regulator 132. The output of manifold 136 is input to a gas distribution device, such as a multi-injector showerhead 140. Although manifolds 128 and 136 are shown, a single manifold may be used. Showerhead 140 according to the principles of the present invention is configured to be tilted during processing of substrate 112, as described in more detail below.

[0033] In some examples, a resistive heater 160 may be used to control the temperature of the substrate support 104. The substrate support 104 may include a coolant channel 164. A cooling fluid is supplied to the coolant channel 164 from a fluid reservoir 168 and a pump 170. Pressure sensors 172, 174 may be disposed in the manifold 128 or the manifold 136, respectively, to measure the pressure. A valve 178 and a pump 180 may be used to evacuate reactants from the process chamber 108 and / or control the pressure within the process chamber 108.

[0034] The controller 182 includes a dosing controller 184 that controls the dosing provided by the multi-injector showerhead 140. The controller 182 also controls the delivery of gases from the gas delivery system 120. The controller 182 utilizes the valve 178 and the pump 180 to control the pressure in the process chamber and / or the evacuation of reactants. The controller 182 controls the temperature of the substrate support 104 and the substrate 112 based on temperature feedback in the substrate support, such as from a sensor (not shown) and / or a sensor measuring the coolant temperature (not shown).

[0035] In some examples, the substrate processing system 100 can be configured to etch the substrate 112 within the same processing chamber 108. For example, as described in more detail below, according to the present disclosure, the substrate processing system 100 can be configured to perform both the trimming step and the spacer deposition step. Therefore, the substrate processing system 100 can include an RF generation system 188, which is configured to generate and provide RF power (e.g., a voltage source, a current source, etc.) to one of a lower electrode (e.g., as shown, the bottom plate of the substrate support 104) and an upper electrode (e.g., the showerhead 140). By way of example only, the output of the RF generation system 188 will be described herein as an RF voltage. The other of the lower electrode and the upper electrode can be DC grounded, AC grounded, or floating. By way of example only, the RF generation system 188 can include an RF generator 192, which is configured to generate an RF voltage fed by a matching and distribution network 196 to generate a plasma within the processing chamber 108 to etch the substrate 112. In other examples, the plasma can be generated inductively or remotely. As shown for illustrative purposes, although the RF generation system 188 corresponds to a capacitively coupled plasma (CCP) system, the principles of the present disclosure may also be implemented in other suitable systems, such as, by way of example only, a transformer coupled plasma (TCP) system, a CCP cathode system, a remote microwave plasma generation and transport system, and the like.

[0036] The controller 182 according to the present disclosure is also configured to adjust the RF power and / or the duration of an etching step (eg, a trim step) to compensate for changes in the etch rate caused by material accumulation on surfaces within the processing chamber 108 .

[0037] Now refer to Figures 2A-2K , which describes an exemplary SADP process. Figure 2A A hard mask layer 204 is shown including, for example, a substrate 200 formed thereon. By way of example only, the substrate 200 includes a silicon (Si) substrate, and the hard mask layer 204 is made of silicon nitride (Si3N4), although other materials may be used. A plurality of core layers (e.g., mandrel layers) 208, 212, and 216 are deposited on the hard mask layer 204 (e.g., using chemical vapor deposition, or CVD). By way of example only, the core layers 208, 212, and 216 may include amorphous silicon (a-Si). In some examples, the core layers 208, 212, and 216 may have a height of about 50-150 nm (e.g., 100 nm). A patterned layer (e.g., a patterned photoresist layer or mask) 220 is formed on the core layer 216 and patterned using photolithography techniques.

[0038] The substrate 200 including the hard mask layer 204, the core layers 208, 212 and 216, and the mask 220 is placed in a processing chamber (e.g., an inductively coupled plasma chamber of an etching tool). Figure 2B As shown, the core layer 216 is etched (e.g., using anisotropic etching or other processing) to form a plurality of mandrels 224. During the etching of the core layer 216, the mask 220 protects the portion of the core layer 216 corresponding to the mandrels 224. If the mask 220 is a photoresist mask, the mask 220 can be removed using an oxygen-containing plasma. If the mask 220 is a material similar to the spacer layer 228 described below, the mask 220 can remain on the mandrels 224 and can be etched during the etching of the spacer layer 228.

[0039] exist Figure 2C , the spacer layer 228 is deposited on the substrate 200 (i.e., on the core layer 212 and the mandrel 224). By way of example only, ALD may be utilized to conformally deposit the spacer layer 228, such as oxide-based deposition (using precursors including silicon tetrachloride (SiCl4), silane (SiH4), etc.), nitride-based deposition (using precursors including molecular nitrogen, ammonia (NH3), etc.), and / or carbon-based deposition (using precursors including methane (CH4), methyl fluoride (CH3F), etc.).

[0040] In one example, a SiCl4 precursor is used in the presence of O2 to deposit the spacer layer 228. Other exemplary process parameters for performing the deposition of the spacer layer 228 include a temperature variation between a minimum temperature below 10°C and 120°C, a plasma power between 200 and 1800 W, a bias voltage from 0 to about 1000 volts, and a chamber pressure between 2 mTorr and 2000 mTorr.

[0041] In some examples, a trimming step can be performed on the mandrels 224 before depositing the spacer layer 228. For example, in the trimming step, the mandrels 224 can be etched to adjust the width of the mandrels 224 and the size of the spacer layer 228.

[0042] exist Figure 2D In some examples, the spacer layer 228 is etched (e.g., using an anisotropic etching process) to remove portions of the spacer layer 228 from the core layer 212 and the upper surface of the mandrel 224, while allowing the sidewall portions 232 of the spacer layer 228 to remain. Figure 2D After the etching described in , a breakthrough step (e.g., fluoride-containing plasma treatment) may be performed. In addition, depending on the material of the spacer layer 228, an oxygen-containing plasma treatment may be performed before the fluoride-containing plasma treatment. Figure 2E In the embodiment of the present invention, the mandrel 224 is removed (eg, using an anisotropic etch). As a result, the sidewall portion 232 remains formed on the substrate 200 .

[0043] like Figure 2FAs shown, the core layer 212 is etched (e.g., using anisotropic etching or other processing) to form a plurality of mandrels 236. During the etching of the core layer 212, the sidewall portions 232 are used as a mask to protect the portions of the core layer 212 corresponding to the mandrels 236. The sidewall portions 232 may be removed in an additional plasma etching step, during etching of the spacer layer 240 as described below, and the like.

[0044] exist Figure 2G , spacer layer 240 is deposited on substrate 200 (i.e., core layer 208 and mandrel 236). By way of example only, spacer layer 240 can be conformally deposited using ALD in a manner similar to spacer layer 228. In some examples, a trimming step can be performed on mandrel 236 prior to depositing spacer layer 240.

[0045] exist Figure 2H In some examples, the spacer layer 240 is etched (e.g., using an anisotropic etching process) to remove portions of the spacer layer 240 from the core layer 208 and the upper surface of the mandrel 236, while allowing the sidewall portions 244 of the spacer layer 240 to remain. Figure 2H After the etching described in , a breakthrough step (e.g., fluoride-containing plasma treatment) may be performed. In addition, depending on the material of the spacer layer 240, an oxygen-containing plasma treatment may be performed before the fluoride-containing plasma treatment. Fig.2I In the embodiment of the present invention, the mandrel 236 is removed (eg, using an anisotropic etch). As a result, the sidewall portion 244 remains formed on the substrate 200 .

[0046] like Figure 2J As shown, the core layer 208 is etched (e.g., using anisotropic etching or other processing) to form a plurality of mandrels 248. During the etching of the core layer 208, the sidewall portions 244 are used as a mask to protect the portions of the core layer 208 corresponding to the mandrels 248. The sidewall portions 244 may be removed, for example, in an additional plasma etching step, such as Figure 2K shown.

[0047] like Figure 2K As shown, the SADP process results in mandrels 248 being formed in a spaced pattern on the substrate 200 (eg, on the hard mask layer 204). The spacing between the mandrels 248 is based on Fig.2I The spacing between the side wall portions 244 shown in FIG. 2 is determined by the spacing between the side wall portions 244, which in turn is determined by Figure 2E244 and the sidewall portions 232, and thus the spacing between the mandrels 248. Therefore, a trimming step may be performed on the mandrels 236 and the mandrels 236 to ensure uniform spacing between the mandrels 248. For example, the respective widths of the mandrels 236 and the mandrels 236 may be trimmed to achieve uniform spacing, such that a=b=c, as Figure 2K shown.

[0048] Now refer to Figure 3A , 3B , 3C and 3D, depict exemplary finishing steps for a SADP process. For simplicity, only a single core layer 300 and mandrel 304 are shown. Figure 3A , the mandrel 304 is shown before a trimming step (e.g., after an etching step for forming the mandrel 304 on the core layer 300, e.g. Figure 2B ). The width of the mandrel 304 corresponds to the critical dimension CD1. Figure 3B As shown, the mandrel 304 is trimmed to adjust the width of the mandrel 304. Therefore, the critical dimension of the mandrel 304 is reduced to CD2. Figure 3C In the embodiment of the present invention, a spacer layer 308 is deposited (eg, conformally deposited using ALD as described above) over the core layer 300 and the mandrels 304.

[0049] Figure 3D Sidewall portions 312 of the spacer layer 308 remaining on the core layer 300 are shown after performing one or more etching steps to remove portions of the spacer layer 308 and the mandrels 304. The spacing (e.g., S1, S2, etc.) between the sidewall portions 312 corresponds to the respective widths (e.g., CD2) of the mandrels 304. Therefore, the pitch of the sidewall portions 312 can be defined as S1+S2+2L, where L corresponds to the line width (i.e., the width of one of the sidewall portions 312).

[0050] Various non-uniformities affect the amount of material deposited (e.g., during an ALD step) and removed (e.g., during an etching step) during processing. Figure 3C The deposition of the spacer layer 308 shown in FIG. Figure 3B The etching of the mandrel 304 during the trim step shown in 2 causes material to be deposited on the surfaces of the processing chamber (e.g., on the inner walls). The accumulation of this deposited material changes the impedance of the processing chamber and the etch rate during the subsequent etching process steps, causing WtW variability of the trim step. Figure 4An example etch volume 400 is shown decreasing (eg, in angstroms for a trim step of a predetermined duration) as material buildup in the chamber increases. As shown, the buildup is measured in terms of the number of trim / deposition cycles relative to the last time the chamber was cleaned. Figure 5 A graph of RF power 500 versus etch amount (e.g., RF power provided during a trim step) is shown. As shown, as RF power 500 increases, the etch amount increases. In this example, the increase is generally linear (e.g., as shown, power y=5x-35, where x corresponds to the etch amount).

[0051] Reference now Figure 6 , Table 600 shows exemplary changes in the amount of etching and the effective power as the accumulation increases (e.g., for a corresponding trimming step of a predetermined time). As shown, as the accumulation increases (e.g., from 900 trimming / deposition cycles to 3900 trimming / deposition cycles), the amount of etching for a trimming step of a predetermined time decreases from 158.66 angstroms to 151.91 angstroms, while the effective power decreases from 758.28 watts to 724.57 watts. Therefore, due to the accumulation increase and the resulting change in the chamber impedance, the effective power decreases. In other words, the effective power is lower than the desired (e.g., set value) power. The ratio of the effective power to the set value power decreases from the ideal ratio of 1.0000 to 0.9555.

[0052] The controller 182 according to the present disclosure is configured to increase the set power (e.g., increase the RF power from a predetermined default set value to an adjusted RF power) based on the cumulative amount. For example, the set power is adjusted according to the power adjustment factor. When the cumulative amount is low (e.g., below 900), the power adjustment factor is 1.0000. In other words, when the cumulative amount is low, the step of adjusting the set power may not be necessary. Conversely, as the cumulative amount increases, the power adjustment factor increases from 1.0000 to 1.0465. For example, if the desired set power is 758.28 watts, at a cumulative amount of 3900, the set power is adjusted according to 1.0465*758.28=793.5400 watts. For a cumulative amount of 3900 at a ratio of effective power to set power, the effective power for a set power of 793.5400 corresponds to 793.5400*0.9555 watts, or 758.23 watts. Therefore, as the accumulation amount increases, the set value power is increased according to the power adjustment factor so that the effective power is maintained at the desired predetermined set value power.

[0053] Figure 7An example graph 700 showing power adjustment factors calculated at various cumulative values ​​(e.g., as indicated by plot points 704). In some examples, the power adjustment factors may be fitted to a curve 708, which is represented by a formula. In one example, the curve 708 is represented by a cubic polynomial. The controller 182 is configured to calculate an adjusted set point power based on the cumulative amount, a desired set point power (e.g., as received as input from a user, a process recipe, etc.), and the formula. In other examples, the controller 182 may store data (e.g., a lookup table) that associates a plurality of cumulative values ​​with corresponding power adjustment factors.

[0054] Reference now Figure 8 , an exemplary method 800 for compensating for accumulation in a processing chamber to minimize wafer-to-wafer (WtW) variability in a trim step begins at 804. At 808, the method 800 determines a correlation between an increase in material accumulation within the processing chamber (and a corresponding change in impedance of the processing chamber) and a change in etch amount for a given trim step. By way of example only, the method 800 collects and stores first data indicating a correlation between a decrease in etch amount (e.g., in angstroms) and an increase in accumulated amount (e.g., measured in the number of trim / deposition cycles since the last time the processing chamber was cleaned, where one cycle corresponds to a trim step and a subsequent spacer layer deposition step). In other examples, the accumulated amount may be measured in another manner (e.g., the total duration of etching and deposition performed within the processing chamber since the last time the processing chamber was cleaned; the total number of substrates processed since the last time the processing chamber was cleaned; the amount of time that has elapsed since the last time the processing chamber was cleaned; etc.). By way of example only, the first data collected corresponds to a decrease in etch amount (e.g., in angstroms) and an increase in accumulated amount (e.g., measured in the number of trim / deposition cycles since the last time the processing chamber was cleaned, where one cycle corresponds to a trim step and a subsequent spacer layer deposition step). Figure 6 The accumulation and etching amount are shown in .

[0055] At 812, method 800 determines a correlation between the etch amount and the RF power. For example, method 800 collects and stores second data indicating a correlation between a change in the RF power provided during the trim step and a corresponding change in the etch amount. For example only, the collected second data may correspond to Figure 5 RF power versus etch amount is shown in graph 500. Generally speaking, increasing RF power increases the etch amount, while decreasing RF power decreases the etch amount.

[0056] At 816, method 800 uses the collected first data and second data to calculate the required RF power to achieve the target etch amount at different cumulative values. Figure 6As described above, method 800 calculates the effective power for a given cumulative value, the ratio of the effective power to the set point power, and the power adjustment factor (e.g., the ratio of the RF power required to compensate the cumulative value relative to the set point power). At 820, method 800 uses the power adjustment factor to calculate and store a correlation between each cumulative value and the corresponding power adjustment factor. For example, the correlation between the cumulative value and the power adjustment factor may correspond to Figure 7 , a formula such as a polynomial representing curve 708, or the like. For example only, controller 182 may store the formula.

[0057] At 824, method 800 performs a trimming step based on the stored correlation between the cumulative value and the power adjustment factor. For example, before the trimming step, method 800 (e.g., controller 182) determines the cumulative amount, determines the power adjustment factor based on the cumulative amount and the stored formula, uses the power adjustment factor to adjust the desired set point power, and performs the trimming step using the set point power adjusted by the power adjustment factor. Method 800 ends at 828.

[0058] Reference now Fig. 9 , which shows an example controller 900 configured to compensate for accumulation in a process chamber according to the present disclosure. The controller 900 includes an RF power control module 904 that controls the amount and duration of RF power provided during a trim step according to the present disclosure. For example, the RF power control module 904 selectively provides a signal to the RF generation system 188 to selectively turn the RF power on and off and adjust the amount of power generated by the RF generation system 188.

[0059] The RF power control module 904 receives a desired setpoint power (e.g., based on a process recipe executed by the controller 900, from the user interface 908, etc.) and an accumulation value (e.g., from an accumulation calculation module 912 configured to determine an accumulation within the process chamber as described above), and retrieves stored data from the memory 916. For example, the stored data corresponds to a formula indicating a correlation between each accumulation value and a corresponding power adjustment factor. The RF power control module 904 calculates an adjusted RF power based on the determined accumulation, the setpoint power, and the extracted data and controls the RF generation system 188 accordingly.

[0060] In another example, instead of and / or in addition to adjusting the amount of RF power to compensate for the decrease in etch rate caused by the accumulation in the process chamber, the controller 900 can be configured to adjust the duration of the trim step. More specifically, the duration of the trim step can be increased to compensate for the decrease in etch rate. For example, the RF power control module 904 receives the desired set point power, the duration of the trim step, and the accumulation, and retrieves stored data from the memory 916 indicating a correlation between each accumulation and a corresponding trim step duration adjustment factor. In an example where the process recipe indicates a trim step duration D, the RF power control module 904 is configured to adjust the duration D based on the adjustment. adj =(duration adjustment factor)*duration D to adjust duration D. For example, the duration adjustment factor may be calculated based on the cumulative values ​​according to a formula associating each cumulative value with the corresponding duration adjustment factor in a manner similar to the calculation of the power adjustment factor described above.

[0061] The foregoing description is merely illustrative in nature and is by no means intended to limit the present disclosure, its application or use. The broad teachings of the present disclosure can be implemented in various forms. Therefore, although the present disclosure includes specific examples, the true scope of the present disclosure should not be so limited, because when studying the drawings, the specification and the appended claims, other modifications will become apparent. It should be understood that, without changing the principles of the present disclosure, one or more steps in the method can be performed in different orders (or simultaneously). In addition, although each embodiment is described above as having certain features, any one or more of those features described relative to any embodiment of the present disclosure can be implemented in the features of any other embodiment and / or combined with the features of any other embodiment, even if the combination is not clearly described. In other words, the embodiments described are not mutually exclusive, and the replacement of one or more embodiments with each other remains within the scope of the present disclosure.

[0062] Various terms are used to describe the spatial and functional relationships between elements (e.g., between modules, between circuit elements, between semiconductor layers, etc.), including "connected," "engaged," "coupled," "adjacent," "next to," "on top of," "above," "below," and "disposed." Unless the relationship between a first and a second element is explicitly described as "direct," when such a relationship is described in the above disclosure, the relationship can be a direct relationship, in which there are no other intervening elements between the first and second elements, but can also be an indirect relationship, in which there are one or more intervening elements (spatially or functionally) between the first and second elements. As used herein, the phrase "at least one of A, B, and C" should be interpreted to mean a logical (A or B or C), using a non-exclusive logical OR, and should not be interpreted to mean "at least one of A, at least one of B, and at least one of C."

[0063] In some implementations, the controller is part of a system, which can be part of the above examples. Such a system can include a semiconductor processing device, which includes one or more processing tools, one or more chambers, one or more platforms for processing, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems can be integrated with electronic devices for controlling their operations before, during, and after the processing of semiconductor wafers or substrates. The electronic device can be referred to as a "controller", which can control various components or subcomponents of one or more systems. Depending on the processing requirements and / or system type, the controller can be programmed to control any process disclosed herein, including the delivery of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and operation settings, wafer transfer in and out tools and other transfer tools and / or load locks connected to or connected to a specific system through an interface.

[0064] In general, a controller can be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. The integrated circuit can include a chip in the form of firmware that stores program instructions, a digital signal processor (DSP), a chip defined as an application specific integrated circuit (ASIC), and / or one or more microprocessors, or a microcontroller that executes program instructions (e.g., software). The program instructions can be instructions sent to the controller in the form of various individual settings (or program files) that define operating parameters for performing a specific process on or for a semiconductor wafer or system. In some embodiments, the operating parameters can be part of a recipe defined by a process engineer to complete one or more processing steps during the manufacture of one or more (kinds of) layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0065] In some implementations, the controller may be part of or coupled to a computer that is integrated with the system, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller may be in the "cloud" or all or part of a wafer fab host system that may allow remote access to wafer processing. The computer may enable remote access to the system to monitor the current progress of a manufacturing operation, check the history of past manufacturing operations, check trends or performance criteria for multiple manufacturing operations, change parameters of a current process, set processing steps to follow the current process, or start a new process. In some examples, a remote computer (e.g., a server) may provide a process recipe to the system via a network (which may include a local network or the Internet). The remote computer may include a user interface that enables input or programming of parameters and / or settings, which are then sent from the remote computer to the system. In some examples, the controller receives instructions in the form of data that specify parameters for each processing step to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool that the controller is configured to interface with or control. Thus, as described above, the controller may be distributed, for example, by including one or more discrete controllers networked together and working toward a common purpose (e.g., the process and control described herein). An example of a distributed controller for such a purpose is one or more integrated circuits on a chamber communicating with one or more integrated circuits remotely (e.g., at a platform level or as part of a remote computer), which combine to control the process on the chamber.

[0066] Example systems may include, but are not limited to, plasma etch chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, chamfer edge etch chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, atomic layer deposition (ALD) chambers or modules, atomic layer etch (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and any other semiconductor processing system that may be associated with or used in the manufacture and / or preparation of semiconductor wafers.

[0067] As described above, depending on one or more processing steps to be performed by the tool, the controller can communicate with one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout the factory, a host computer, another controller, or tools used in material transport to transport wafer containers to and from tool locations and / or load ports in a semiconductor manufacturing facility.

Claims

1. A controller, comprising: a memory storing data associating accumulated values ​​with corresponding adjustment factors, wherein the accumulated values ​​correspond to accumulation of material on a surface within a processing chamber, the processing chamber being configured to perform etching and deposition on a substrate, and wherein the corresponding adjustment factors correspond to adjustments to a control parameter for radio frequency power provided to the processing chamber when performing an etching step of a patterning process; a cumulative calculation module configured to calculate a first cumulative value indicating a cumulative amount of the material; as well as The radio frequency power control module is configured to: receiving the first accumulated value, receiving at least one of a setpoint power to be provided during the etching step and a duration of the etching step, extracting the stored data from a memory, adjusting the control parameter based on the at least one of the first cumulative value, the setpoint power and the duration of the etching step, and the stored data, and The RF power provided to the process chamber during the etching step is controlled according to the adjusted control parameter.

2. A controller according to claim 1, wherein the control parameter is the amplitude of the RF power, and wherein the RF power control module is configured to use the stored data to determine a first adjustment coefficient corresponding to the first cumulative value and to adjust the amplitude of the RF power according to the first adjustment coefficient. 3 . The controller of claim 2 , wherein the stored data is a polynomial that relates the accumulated value to the corresponding adjustment coefficient.

4. The controller according to claim 2, wherein the first adjustment coefficient is a ratio of (i) a magnitude of the RF power required to compensate for the accumulation to (ii) the set value power. 5 . The controller according to claim 2 , wherein the RF power control module is configured to multiply the set value power by the first adjustment coefficient to adjust the control parameter.

6. The controller according to claim 1, wherein the cumulative calculation module is configured to calculate the first cumulative value based on at least one of the number of etching steps performed in the processing chamber, the number of cycles of the etching step and the deposition step performed in the processing chamber, the total duration of the etching step and the deposition step performed in the processing chamber, and the number of substrates processed in the processing chamber.

7. A controller according to claim 1, wherein the control parameter is the duration of the etching step, and wherein the RF power control module is configured to use the stored data to determine a first adjustment coefficient corresponding to the first cumulative value, and to adjust the duration of the etching step according to the first adjustment coefficient.

8. The controller of claim 7, wherein the first adjustment factor corresponds to an amount to increase the duration of the etching step to compensate for the build-up.

9. The controller of claim 7, wherein the RF power control module is configured to multiply the duration of the etching step by the first adjustment factor to adjust the control parameter.

10. The controller of claim 7, wherein the etching step is a trimming step.

11. A system comprising a controller according to claim 10, wherein the controller is further configured to perform a spacer layer deposition step within the processing chamber after the trimming step.

12. A substrate processing method, comprising: storing data associating accumulated values ​​with corresponding adjustment factors, wherein the accumulated values ​​correspond to accumulation of material on a surface within a processing chamber, the processing chamber being configured to perform etching and deposition on a substrate, and wherein the corresponding adjustment factors correspond to adjustments to control parameters for radio frequency power provided to the processing chamber when performing an etching step of a patterning process; calculating a first cumulative value indicating a cumulative amount of the material; receiving at least one of a setpoint power to be provided during the etching step and a duration of the etching step, adjusting the control parameter based on the at least one of the first cumulative value, the setpoint power and the duration of the etching step, and the stored data, and The RF power provided to the process chamber during the etching step is controlled according to the adjusted control parameter.

13. The method according to claim 12, wherein the control parameter is the amplitude of the radio frequency power, the method further comprising: determining a first adjustment factor corresponding to the first cumulative value using the stored data; and The amplitude of the radio frequency power is adjusted according to the first adjustment coefficient.

14. The method of claim 13, wherein the stored data is a polynomial relating the cumulative value to the corresponding adjustment coefficient.

15. The method of claim 13, wherein the first adjustment coefficient is a ratio of (i) a magnitude of the radio frequency power required to compensate for the accumulation to (ii) the set value power.

16. The method of claim 13, further comprising multiplying the set value power by the first adjustment coefficient to adjust the control parameter.

17. The method according to claim 12 further comprises: calculating the first cumulative value based on at least one of the number of etching steps performed in the processing chamber, the number of cycles of etching steps and deposition steps performed in the processing chamber, the total duration of etching steps and deposition steps performed in the processing chamber, and the number of substrates processed in the processing chamber.

18. The method of claim 12, wherein the control parameter is the duration of the etching step, the method further comprising: using the stored data to determine a first adjustment factor corresponding to the first cumulative value, and The duration of the etching step is adjusted according to the first adjustment factor.

19. The method of claim 18, wherein the first adjustment factor corresponds to an amount to increase the duration of the etching step to compensate for the build-up.

20. The method of claim 18, wherein the etching step is a trimming step, the method further comprising: performing a spacer layer deposition step in the processing chamber after the trimming step.

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